openstack team mailing list archive

[Major Hayden <major@xxxxxxxx>]

On Apr 13, 2012, at 4:31 AM, ikke wrote:

> 2.5. virtual HW manager (guest isolation)
>      - Any plans to integrate a piece from which a state of guest could
>        be reliably queried, e.g. guaranteeing that if I ask to power
> off another
>        guest, it get's done in given time (millisecs), and not
> pending on e.g. some tcp
>        timeout, and thus leading to split brain case of running two
> similar guest
>        simultaneously. E.g. starting another guest to replace shut
> down one, but
>        due some communications error the first one didn't really shut
> before the
>        new one is already up.
>     - should be able to reliably cut down the guests network and disk access to
>       guarantee the above case

This would be a huge win for clustering.

Having a reliable and immediate STONITH capability within a virtual environment would be really handy for environments which have sensitive needs for shared storage (whether it's remote iscsi storage or DRBD).  It would be relatively trivia to assemble a fencing daemon to make requests to the API to hard reboot a misbehaving member of a cluster.

Good points!

-- 
Major Hayden